Comment # 9 on bug 1014450 from Takashi Iwai

This doesn't look like a kernel problem, but rather an infamous race at boot
up.
It explains why the manual X test failed.

I've observed a similar issue on my HSW machine, too, but only occasionally. 
And, in my case, it's XFCE desktop.

What display manager are you using for Mate?  Is it lightdm?  If so, it's as
same as XFCE, at least, and it can be a suspect.  Or if it's gdm, we should see
the issue on GNOME as well.

Adding Stefan to Cc.  We may test it locally as well.

Meanwhile, as a usual suspect, please try to disable plymouth.  The best would
be completely uninstalling the stuff,
  # zypper rm -u plymouth

or you can boot with plymouth.enable=0 option to disable in runtime, too.
I guess the issue still persists, but let's make sure.

The lack of network might be a similar cause, but it's not sure.  Is the
network setup via NetworkManager or wicked?  Anyways, you'd better split to two
bug reports, one for the wrong X startup and another for the network issue.